Shaving device



' Oct. 1, 1940. K MGALL 2,216,672

SHAVING DEVICE Filed Aug. 13, 1936 I 7 Patented Oct. 1, 1940 Y UNI-TED SHAVING DEVICE 5 "Philip K. McGallj Newark pN. J., ass'ignor to 'Art Metal Works, Inc., New of New Jersey n ark,N. J., a corporation Application August 13, 1936, Serial sums The invention relates toshaving devices and has as an object the provision of a device of this character operating purely by rotary motion.

'It is an object of the invention to provide a device having'a rotor provided. with a helical cutting edge of relatively... close turns cooperating with cutter bars presenting'cutting edges opposed to the action of said helical. edge to provide a shearing action therewith. g

It is a further object of the invention to provide a helical'cutting edge revolving closely ad:- jacent but out of actual contactwith cutting edges carried by cutter bars, the edges spaced from each other a distance less than the diameter of a hair.

It is afurther object of the invention to providea device of this character. wherein separated hairs are conveyed to an end of the device for discharge. v M

It is a further object. of the inventionto provide cutting edges of the character described forming with each other an angle such as to avoid pullingupon the hairs. I a

It is a further object of the invention to provide a device of this character having the shaving portion arrangedat a convenient angle to the casing containing the motor,

Further objects of the invention will appear from the following description when readin connection with the accompanying drawingshowing an illustrative embodiment of the invention, and

wherein:

Figure 1 is a side elevation; 'Fig. 2 is an edge vview seen from Figure 1;

Fig, 3 is a bottom plan viewof the cutter portion of the device shown upon an enlarged scale;

Fig; '4 is a longitudinal section on line '4-4 of Fig.3; and

I Fig.5 is a vertical transversesection on line 5-5 of Figure 4.

As shown the device comprises a handle portion I containing an electric motor ll of any desired character'provided with an attachment receptacle 1!.

To start the motor into operation there is shown a thumb, wheel l3 rigidly mounted upon theshaft H of the motor, the thumb wheel l3 being exposed in a cavity l at a side of the handle Ill. When the current is turned on, the motor may or may not start immediately'into rotation. If it does not, the thumb of the operator may be applied to the wheel l3 to give an initial movement, when the motor will start the left of 'and continue to operate but may be stalled "at any time by pressure upon the wheel l3.

The handle I0. is'shown as provided with an extension 16 terminating inannangularly related portion l1 havinga socket portion I8 for reception of the casing 'l9lof the cutter a paratus. The portion llof the handle is desirably split as shown at 20 and a clamp screw 2l is-provided to clamp the casing I9 in position;

The casing I9 is shown as formedwith a cylin drical bore. 22eccentric therewith and for convenience in .usehportions of "this casing are cut away' to provide longitudinal plane surfaces 23,- 24 andaface-oontacting plane' 'surface 25. 'Although the angles between these surfaces are not necessarily 60, yet the three surfaces may be described as substantially one-half of ahexagon; The surface 25 is provided with a plurality of slits 26 to leave cutter bars 21, the inner portions of which present cuttingedges.

-Rotatable in thecasing I9 is a'rotor 28'driven from the motor shaft 14 through the medium of a universal joint 29. It will be obvious,=that the end portion of'the motor shaft I4 may be a flexible shaft having a coupling of any character with the shaft 3ll of the rotor 28. 'I'he'rotor 28 is' shown as formed with; a helix 3| comprising spaced turns separated by helical groove 32 so 'a'sf to provide a helical cutting edge upon thelead ingedge of the turns of thehelix. To-keep the outer face of the helix 3| from actual contact with the cutter bars 21, non-cut- A tingportions '33, 34 thereof arem'ade slightly larger thanthe remainder and of such a dimensionas to form a close turning fit with the bore of the casing. The clearance thus provided between the helical cutting edge and the cutter bars 21 may beof the order of .0005 of an inch, in other words, the portions 33, 34 are .001 of an inch larger in dimension than the cutting por- To permit the discharge of particles' of hair clipped by the helical edge coacting with the edges of the cutter bars, the end 35 of the casing is shown as cut away at its lower portion to I provide a discharge opening 36.

- cutting edge to the axis of the rotor is substantially 3.25 degrees. vIt is found that if the slits separating the cutter bars 21 are at right angles to the axis, the resulting angles of the helical turns to the cutting edges carried by the bars of substantially 3.25 degrees will tend to cause the hairs to be dragged laterally before they are severed, resulting in a pulling on the beard. On the other hand, if the angle between the helical cutting edge and the edges carried by the bars is too small, the hairs will tend to be rolled along.

It is therefore preferred as shown to form the slits 26 separating-the cutting bars at an angle to the axis of the rotor and it has been found by experiment that with the rotor formed as described, this angle of the slits to the axis should.

be about 2.50 degrees, thus providing an angle between the relatively moving cutting edges of substantially .75 of a degree. This angle is found to be somewhat critical and it is at present preferred to make this angle not substantially more than one degree or less than about .50 of a degree.

To guide the hairs into the spaces between the cutter bars, the ends of the bars at the angles between the surfaces 23, 24 and the surface 25 are desirably pointed as indicated at 31, Figure 3.

The thickness of the cutter bars 21 at the lowest portion of the bore 22 is made as little as possible consistent with the necessary strength of the bars, and this'strength is assisted by their thickening at the points 38, 39, Figure 5.

The lower surface 25 of the casing I9 is desirably made continuous with the lower'surface 40 of the handle portion I! and to this end the socket for reception ofthe casing l9 may be cut away as indicated at 4|, Figure 3, the portion [1 being formed with a shoulder 42 to be abutted by the lower wall of the casing l9.

If v the spacing between the turns 3| of the helix be made exactly the same as the spacing of the cutter bars 21, the entire length of'the helical cutting edge will be coacting with the edges of the cutter bars at the same instant, placing anundue strain upon the motor. To avoid this action, the spacing is, as indicated in Figure 4, made slightly different so that when the portions indicated between the lines 43, 44 and for instance the space indicated between lines 45 and '46 are in the act of cutting, other portions will be out of action, therefore separating the cutting action into traveling zones, non-active zones being represented at any instant by portions wherein the edges of the helical turns 3| have closed the slits. Minor changes may be made in the physical embodiment of the invention within the scope of the appended claims without departing from the spirit thereof.

I claim:

1. A shaving device comprising: a casing having a bore and a plurality of transverse slits opening through a wall thereof to form cutter bars each presenting a cutting edge at the surface of said bore; a rotor revoluble in said bore; a closely spiraled helical cutting edge carried by said rotor coacting in shear with said first named cutting edges; means to hold said coacting cutting edges out of actual contact; and means to cause revolution of said rotor.

2. A shaving device comprising: a cutter casing having a bore eccentric therein and an end wall; said casing exteriorly semi-cylindrical at the thickest portion of its wall and substantially semi-hexagonal about the remainder of its exterior; the plane surface standing between the remaining plane surfaces of the semi-hexagonal portion of the casing being at the thinnest portion of the wall; said first named plane'surface wall having a plurality of transverse slits defining cutter bars presenting cutting edges at a surface of said bore with the slit adjacent the closed end of the casing spaced therefrom; a rotor revoluble in said casing and abutting said closed end; a closely spiraledhelical rib carried by said rotor extending to said casing abutting end thereof and presenting a helical cutting edge to coact with said cutting edges; anon-cutting portion of said rib adjacent the casing abutting end thereof and a non-cutting portion of the rotor adjacent the remaining end thereof having a close running fit in said bore and the cutting portion of the rotor of slightly less diameter to hold the cutting edges out of actual contact; and means to drive said rotor;

3. A shaving device comprising: a rotor comprising a central rigid core and a helical rib carried by said core presenting a helicalv cutting edge; a casing having a bore housing said rotor; transverse, spaced cutter bars carried by said casing at one portion of said boreeach presenting a cutting edge at the surface of said bore to coact with said helical cutting edge; the spacing of said cutter bars differing from the pitch of said hell cal cutting edge to cause the turns of said helical cutting edge to coact at all times with a nonsuccessive plurality of said cutter bar edges; and means to cause revolution of said rotor.

4. A shaving device comprising: a rotor comprising a central rigid core and a helical rib carried by said core presenting a helical cutting edge; a casing having a bore housing said rotor; transverse, spaced cutter bars carried by said casing at one portion of said bore each presenting a cutting edge at the surface of said bore to coact with said helical cutting edge; the spacing of said cutter bars differing from the. pitch of said helical cutting edge to cause the turnsof said helical cutting edge to'coact at all times with a non-successive plurality of said cutter bar edges; bearings for the rotor in the casing adjacent the respective ends of said helical cutting edge.

PHILIP K. MCGALL. 

